This invention relates generally to truck bed covers and more particularly to security or hard tonneau covers for pickups.
Various security and hard tonneau covers are commercially available. These hard covers serve the purpose of keeping the contents of the truck bed out of view, are generally weather tight and prevent unauthorized entry into the truck bed.
Most hard covers are pivotally mounted to the front of the truck bed and open clamshell-like to the rear. This is mechanically simple, however access to the front of the truck bed is severely restricted. Cargoes tend to shift forward in truck beds, hence items tend to migrate to the front of the tuck bed where they are least accessible. If the cargo extends above the sidewalls of the truck bed, the cover cannot be closed. Even with the cover open, having the front of the cover hinged to the front of the truck bed prohibits hauling large items such as home appliances or motorcycles. Driving with this type of cover in the open position obliterates the driver""s rear view.
Another type of hard cover is marketed as the SILVER SHIELD. Both sides of the cover open on folding legs; either or both sides can be open at a time. It has the advantage of good access to the entire truck bed and has proven popular with tradesmen who need to secure their tools while maintaining good access to the truck bed. Another advantage is that the truck can be driven with the cover in the open position to haul items which extend above the sides of the truck bed. A disadvantage is the tedious opening and closing procedure which involves folding two legs on each side and the insertion or removal of locking pins.
Another hard cover is described in U.S. Pat. No. 5,364,154 entitled xe2x80x9cLiftable Rigid Truck Bed Coverxe2x80x9d. This hard cover opens on four legs operating as a parallelogram. From the closed position, the cover lifts upward and rearward along the arc of the pivoting legs. This achieves good access to the pickup bed without the tedium of opening and closing a Silver Shield. However, the geometry of the opening and closing mechanism requires four latch points to secure the cover in the closed position. To keep the cover in the open position, this cover utilizes a height establishing mechanism which locks pins into one of several holes. These mechanisms for locking the cover in the open and closed positions make it expensive to manufacture and more complex than other truck bed covers.
It is clear that there is a need for an improved security cover for pickup beds.
The invention is a truck bed cover lifting and locking apparatus which provides good access to the truck bed with a minimum of mechanical complexity and excellent operating ease.
The truck bed cover is secured to a bed of a truck using two leg assemblies which are connected to the bed of the truck. In the preferred embodiment, these leg assemblies are generally xe2x80x9cUxe2x80x9d shaped with their associated extension of the leg assemblies connected to the bed of the truck.
The cover is swivelly connected to these leg assemblies allowing the cover to be raised or lowered. The cover is ideally supported by two linear members which extend between the leg assemblies and onto which the cover (ideally a rigid cover) is supported.
In an xe2x80x9cupxe2x80x9d position, the cover is locked in position using a locking bar which extends from the cover to the extensions of the rear-most leg assembly. The locking bar is ideally U-shaped with its legs extending into locking mechanisms located on the extensions of the rear-most leg assembly.
To release the locking bar from the locking mechanism on the leg assembly, a user pulls a handle on the locking bar. This downward pull is translated into an upward motion of the locking bar to effectuate a release allowing the cover to be lowered onto the bed of the truck.
In a xe2x80x9cdownxe2x80x9d position, the cover is locked to the bed of the truck using engagement studs positioned near the cab of the truck. These engagement studs interact with engagement mechanisms (located on the forward-most leg assembly, the linear frame members or the cover).
In more detail, the invention opens the truck bed cover by lifting it upward and rearward on an approximately 90 degree arc with a plurality of lifting legs. The open cover is held in a generally horizontal position above the truck bed and tailgate. This provides shade over the tailgate.
A unique feature of the invention is the sliding pivot point on the front pair of lifting legs. The front legs are slightly shorter than the rear legs, hence the invention is not a perfect parallelogram. As the cover is closed, the shorter front legs travel in a shorter arc than the longer rear legs. If all of the pivot points of this apparatus were at fixed points, the apparatus would bind up before reaching a closed position. However, as the apparatus nears the closed position, the front legs traverse forward on a sliding pivot point, which in the preferred embodiment, are slotted holes in which pivot bolts reside. This forward traversing action of the front legs allows the apparatus to engage a locking means at the front of the truck bed as the cover reaches the closed position. Another benefit of this automatic front locking means is that it captures the gas lift spring used in the preferred embodiment in a closed position. Rear locking means, which are commonly built into commercially available truck bed covers, secure the rear of the cover.
The sliding pivot point of the front lifting legs makes the apparatus easier to open, because the user can get lifting momentum started at the rear of the cover before the front of the cover begins to raise. As the front lifting legs traverse rearward, the front locking means is disengaged, allowing the front of the cover to begin moving upward with the assistance of a lifting means such as a gas spring.
The apparatus also has a locking means to automatically lock the cover in the open position when it is raised. In the preferred embodiment, a U-Shaped locking tube is utilized to lock the rear lifting legs in their upright position. This U-shaped locking tube is spring loaded at the two pivot points to bias the tube ends downward. The U-shaped locking tube is slightly narrower than the rear lifting legs and fits inside the rear lifting legs. The rear lifting legs have latch points for the locking tube, and as the rear lifting legs reach their open position, the locking tube moves down by gravity and spring pressure and engages the latch points on the rear lifting legs. This prevents the cover from closing until the user releases the locking tube by pulling down the rear hoop portion of the locking tube.
In this context then, the invention provides for an improved pickup cover in which the effective operating radius of the front lifting legs are modified to achieve a front traversing action as the apparatus is near the closed position. In the open position, the front lifting legs are effectively shorter than the rear lifting legs. As the apparatus closes, the front lifting legs reach the same or similar length as the rear lifting legs by use of sliding pivot points or other means of effectively varying the length of the front lifting legs. This translates into a frontward traversing action at the front of the apparatus which enables the invention to engage a front locking means as the apparatus reaches the closed position. This has a number of benefits, such as the front locking means preventing unauthorized entry into the front of the truck bed cover and it also captures the gas spring in the closed position. Another benefit is that as the user opens the bed cover, the rear of the cover begins to lift before the front does. This lets the user impart some opening inertia into the rear part of the cover before the front begins to lift, hence the user does not have to get the entire cover moving at once from a dead stop.
A much less significant part of the apparatus is the powered open position locking means. In this embodiment, an electric linear actuator is utilized to obtain the required motion.
The invention provides for a variety of benefits, including, but not limited to, a truck bed cover with:
1) a lifting and locking apparatus which overcomes the disadvantages of the prior art;
2) a lifting and locking apparatus which provides good access to the entire truck bed by lifting the entire cover into a generally horizontal position above the truck bed and tailgate;
3) a lifting and locking apparatus which requires a minimum of moving parts to provide excellent reliability and to minimize manufacturing costs;
4) a lifting and locking apparatus with an open position locking means which automatically locks the cover when it is raised, to prevent unintentional or accidental closing of the cover;
5) a lifting and locking apparatus which automatically secures the front of the cover in a locked position when it is closed to eliminate the need for separate locking means for the front of the cover;
6) a lifting and locking apparatus which can be retrofitted to existing truck bed covers or manufactured with new truck bed covers.